Higan

Having dissed the flowering cherries I have to put in a word for the Higan cherry, Prunus subhirtella pendula. It is really something, like a ruined cathedral hung with candyfloss.

Like most pendulous trees, it looks at home near water. I could also imagine it hanging above a steep ravine.

Taste

This spring I studied the flowering cherries. I thought I should get some clear ideas about them because, in my head, the varieties mostly run together.

Then the crabapples bloomed. What a relief to be able to let go of the cherries and just enjoy the crabs. Their fragrance is as fine as the lindens, and it’s as free. In many crabs the buds are deep pink, but when the flowers open, they are white. I keep an eye on the crabapples for the day when the two-tone effect peaks.

The cherries bore me, but the crabs are a delight. I don’t know why. The extravagance of both is comparable. And objectively, most of the cherries are better garden trees: they have a tidy habit compared to the crab’s awkwardness, more disease resistant foliage, better bark and fall color. But the blooming crabs, especially the straight species Malus floribunda, are a high point of spring for me.

I think knowledge and involvement with plants only serves to sharpen these kinds of preferences. And it’s a good thing. Preferences should be exercised. Gardens holds together when there is an abiding taste behind the thousand choices that guide their creation. They go wrong when they try to have a little of everything.

Better than Forsythia Part 2

I feel a little chastened about my screed against Forsythia. Last weekend I was in Connecticut, among people who love it. It looked great along the highways -- I’ll say that for it.

Still I stand by my disapproval of planting Forsythia in Brooklyn.

But say you are planting a typical Brooklyn garden, and you love Forsythia because it’s bright and early. Corylopsis (recommended after the last Forsythia tirade) is too wan and toned-down for your taste. What you want is uninhibited brassiness to go with the tulips and flowering cherries.

So plant Kerria. It’s resoundingly yellow, and, unlike Forsythia, the flowering repeats a little after the initial flush. Dirr says it’s “ideally sited in partial shade.” The leaves are neat, and the stems are distinctly green and ornamental in winter. The photo shows the double flowered variety, which is more common than the more elegant single.

Without a Greenhouse

Every year I overwinter a bunch of cuttings that I take from tender bedding plants. When spring finally rolls around I wonder if it’s worth the trouble.

This sorry lot goes out for a couple of weeks of acclimation before they are planted. Their winter leaves drop so they look worse now that they have all winter, but new growth has broken and they will be fine. I plant them out when the soil is warm.

A few rules to live by during the six months they are inside:

1) Keep them alive but don’t promote growth. Minimal water. No fertilizer. They do as well in little pony packs as 4” pots.
2) Keep the terminal buds on the plants because they produce hormones that promote rooting. The cuttings will get lanky. Plant them out that way and pinch them back once they really get going.
3) Give them as much sun as you can. South windows, etc.
4) Don’t pot them up to get a jump on spring. This sets them back and even kills them.

Ephemerals

I Iwas lucky to see this patch of Bloodroot. The flowers are so fragile they last only a few days -- even less in the warm weather we’ve had. So I saw this bunch at its absolute zenith.

These fiddleheads (I think they belong to the Cinnamon Fern) are covered in astonishing soft fuzzy jackets. I’ve never seen anything like it. The next day, the fuzz had broken apart and fell like rags off the unfurling fiddlehead.

Washtub Azalea

Nobody fusses over this azalea, but it's been comfortable and thriving for many years. It grows in about 8 inches of soil in a galvanized washtub. Over the years a layer of decaying leaves has accumulated – I venture that is all the feeding the azalea gets. The washtub sits in front of a south facing house, shaded by a Zelkova tree.

The plant is perfectly suited to its situation so it really can thrive on neglect.

This is one of my favorite azaleas, a Kurume hybrid called ‘Coral Bells’. Its small, beautifully formed blossoms are a good, strong, warm pink. The color is about as intense as I like to see in April.

A Pegged Rose

Some friends in Connecticut are lucky to have a nice bush of the rose ‘Heritage’.

Few roses have flawlessly graceful, fragrant blossoms on a bush without functional defects, but ‘Heritage’ is such a rose. Its sole shortcoming is a rangy habit. It tends to throw rampant shoots that aren’t quite stiff enough to support themselves - though it’s not quite a climber either. What ‘Heritage’ needs is a low fence to sprawl over.

In my friends’ Connecticut garden ‘Heritage’ grows beside a boulder, and so we tried the old technique of pegging the long shoots over the rock. In March we cut out everything but last year's long shoots and fanned them over the boulder. Their ends were tied with twine to pegs driven into the ground.

Pegging is a nineteenth century method that was used with the Hybrid Perpetuals. The theory is that roses tend to send short spurs bearing flowers from the portions of the main branches that grow horizontally. I’ve found this to be true with climbing roses.

Back with results in June.

Ipheion

Peonies are drop dead gorgeous for a few weeks around Memorial Day. Then, if they don’t get mildew, they are decent citizens that go unnoticed for the rest of the year.

Their emerging foliage is interesting too. It unfurls with gusto. I love how it is set off here in a field of starry Ipheion.

This little bulb is perfectly hardy, leafing out in winter and blooming as the peonies break growth. Eventually the peony foliage will conceal the passing Iphieon. Like peonies, Ipheion resents disturbance. With time a few bulbs can make quite a show. So the two plants settle into a long, unexpected companionship.

Adding something for fall (anemone ‘Honorine Jobert’, say, or chrysanthemum ‘Mary Stoker’) would round out the calendar. The freshness of the fall flowers, in contrast to the patinated peony foliage, will appeal as much as their color.

Ruderal

On April 10 Peter Del Tredici, from the Arnold Arboretum, spoke at MetroHort on Wild Urban Plants. I think he’s on to something.

The gist of his lecture is that urban environments create horticultural conditions (disturbed, compacted soils, expanses of pavement, urban heat island warming, etc.) that support a distinct community of plants. Cosmopolitan in origin, these plants are largely reviled as weeds: ailanthus, black locust, mugwort, bindweed, chicory. We struggle to eradicate them; even legislate against them. Instead we might recognize their possibilities for the ruderal landscape.

(Learning the word “ruderal” was worth the trip up there: “growing in rubbish, poor land, or waste places. From Latin rudera, ruins, rubbish, plural of rudus, broken stone.”)

Del Tredici is working on a book, Wild Urban Plants. It goes to the publisher in October. It sounds like Weeds of the Northeast, horticulturally considered. I look forward to seeing it.

There is a lot wishful thinking about native plants: You can earn a LEED credit by planting a community of natives on imported soil and handing it over to the maintenance man to nurse. I don’t want to discourage well-meaning gestures, but it’s hard to see how this kind of planting accomplishes much in the way of plant conservation. (What is actually needed is a whole preserved ecosystem where the plants can endure in a community of organisms they evolved with – something beyond the purview of green building.)

For urban planting we might look instead to these ruderal “natives” that are so well suited to the actual growing conditions. Del Tredici has planted meadows of yarrow, chicory, goldenrod, and bouncing bet. And the black locust is as fine a tree as grows.

I’d be interested to know if the planting schemes for the High Line consider this line of thinking. Ruderal natives are growing there already.

Little Trees

Shrubs in nursery containers are cute, and people plant a lot of them. Eventually everything gets claustrophobic. Nothing can compete. It’s dismal.

You want to hack them down to size or overhaul the whole place and start fresh. But consider retaining some of the shrubs and limbing them up, creating a grove of little trees. Light is admitted and an understory of shade plants can carpet the ground below. In a confined area a miniature forest is not ridiculous. It gives a settled look. It couldn’t be nicer.

Shrubs that form nice trunks lend themselves to this treatment. Pieris is excellent because of its distinctive undulating habit. Rhododendrons, hollies, euonymus, yews, rose of sharon, mountain laurel and aucuba are all suitable. Suckering shrubs that throw up new shoots from the base – like roses, spirea, and hydrangea – are usually not.

Dotards

Dotards are old trees that are decaying as fast as they are growing. They can go on like this for years -- centuries even -- and they develop fantastically gnarled shapes.

There were two old black locust trees in Tompkins Square, gnarled and full of snags, and beautiful in the way locusts always are. When the city was letting that park go to pieces these trees were neglected. Crows roosted in their dead branches; it couldn’t have been better. Then the city got things in shape. They cut out the dead wood, but nothing looked right. They cut out more limbs; then they took down a whole tree. The city was well meaning, but I think they ought to be protecting venerable treasures instead of pursuing hopeless campaigns to remedy them.

The most famous East Village dotard was the Stuyvesant Pear. Planted in 1647 on a spot that later became the corner of Third Ave and Thirteenth St, it lived until 1867. Until 1862 it bore fruit. There’s a plaque on the wall about it.

The hawthorn in the picture grows in the south west corner of McCarren Park. It’s robust, fruiting heavily every year. I’ve tried to identify it (hawthorns are tricky) and for the life of me I think it’s Crategeus viridis ‘Winter King’, which was introduced in 1955. But it seems impossible that this tree is just 50 years old.

Maybe it’s not ‘Winter King’. Maybe it’s ancient, predating the park, which was called Greenpoint Park prior to being renamed in 1909. (The pool opened in 1936.) Does anyone know how to sort this out?

Trochodendron araliodes

Here’s a fantastic plant that you don't see much. It is one of the best small evergreen trees for city gardens. No broadleaf evergreen comes through the winter with leaves of comparable freshness. (These photos were taken at BBG in March.) It is happy in half sun to half shade on acid, moist woodland soil.

Slow growth, eventually to 20 or 30 feet, may have limited its popularity. (Gardeners are suckered by the promise of rapid growth, but most really handsome plants are slow.)

And then Trochodendron araliodes is a mouthful. The colloquial name, “Wheel Tree”, refers to the disposition of the stamens. It won’t catch on because nothing about the general look of Trochodendron suggests a wheel. (“Ivy Tree” might be more apt, as the leaves resemble the mature growth of English Ivy.)

I saw it once at a plant sale at the wonderful Chinese Garden in Portland, Oregon. Rare Find Nursery lists it online.

PJM

PJM rhododendrons are great container plants for our area. It’s a surprise because rhododendrons and azaleas in general can be tricky in containers. In principle they should be manageable, but I rarely see happy specimens. Usually they’re just hanging on, spoiled by lacebugs.

The PJM hybrids are the workhorses of genus. Many of be best plants I see are growing in more less full sun. The bloom is a frilled, lavender-pink confection that is in poor taste but delightful just the same. After all the excitement the shrub settles into a state of handsome sobriety for the rest of the year. The leaves are small and healthy and they turn an interesting purple / bronze in the winter. Eventually the shrub builds up to about five feet.

Drainage, drainage, drainage: that’s the mantra for rhododendrons, and it shouldn’t be a problem to provide it in containers. I think it’s important to knock a lot of the potting mix out of the rootball when you plant – it’s ok to bang them around a little. Plant the crown high.
I also have a theory that the roots want to be cool. I think they do better if the container is shaded or light colored or made of wood or another insulating material. This is just my theory.

Violas

The easiest, cheeriest thing you can do is plant violas in early spring. They like sun and cool weather and will bloom profusely till the summer gets hot. Their good points:

1) The individual flowers are cute as can be, held neatly above the leaves and borne abundantly.
2) They are fragrant, faintly but definitely, of violets.
3) Lovely blues, yellows, purples and bicolors. Gardeners who love blue have no comparable bedding plant.
4) And then there’s black: the variety called Bowles Black is a deep satiny purple black with a tiny yellow eye. As black as any flower.
5) You can eat them. They don’t taste like much, but a salad strewn with black violas sets a certain tone.
6) They can take spring weather. In this they are far better than pansies, which are like violas, only larger, and get weather beaten. (A general point: plants that bear smaller flowers in profusion are usually more garden worthy than plants with fewer but larger flowers.)
7) No fuss. No need to deadhead. Spring rains being what they are, there’s hardly a need to water. Just let the violas weave through emerging perennials or push them aside to plant summer bedding plants.
8) Their stems are just long enough to cut. A single rose with a couple of violas in a tiny vase is all anyone really needs.
9) When the summer gets hot violas get lanky and peter out. Pull them up. At that time of year a bit of clean up feels good.

Better than Forsythia

Better than Forsythia

The Forsythia is honored April 6 at the Brooklyn Botanic Garden with plants given free to garden members. It’s a point of local identity: In 1940 a garden benefactor, Mrs. Edward C Blum, was instrumental in having forsythia declared the official flower of Brooklyn. It was “…imbued with a message of brotherhood, unity and understanding…” she said.

Forsythia is at its best grown in full sun and allowed to develop into the fountain shape it naturally assumes. The usual cultivars are in the 8 foot by 8 foot range -- too big for most Brooklyn gardens -- so they are routinely hacked with hedge trimmers into manageable shapes. Treated thus they bloom poorly; and because Forsythia is undistinguished after its April bloom, it becomes an eyesore. You see these sad plants all over the borough.

If you must have Forsythia, be sure you have a sunny spot, pick a cultivar suited to the space to have, and prune it by removing entire old branches at their base. Smallish cultivars like ‘Gold Tide’ are better suited to most Brooklyn gardens. There’s one called ‘Bronxensis’ that’s smaller still, practically a ground cover.
If your garden is shaded at all, I recommend you forego Forsythia entirely and grown another east Asian shrub, Corylopsis pauciflora, the Buttercup Winterhazel. It blooms with the forsythia and hangs its pale yellow flowers like bells from the twigs. This poised 4 to 6 foot shrub is better suited to city gardens. Its neat foliage colors gold in autumn.

Spring and All

This is Crocus tomasinianus. Brent and Becky's Bulbs has them for $220 per 1000. They seed and increase if you put off mowing the lawn